The present invention relates to a moisture curable composition, and more particularly to a stablized curable composition containing a hydrolyzable silyl group-containing vinyl polymer having on the vinyl polymer chain end or the side chain thereof at least one silicon atom, to which a hydrolyzable group is linked, per one polymer molecule.
Various silyl group-containing vinyl polymers having silicon atom linked with a hydrolyzable group are known. They have a good adhesion property to inorganic materials based on the hydrolyzable silyl group and cause crosslinking at ordinary temperature by moisture, particularly moisture in the atmosphere, to form cured products having an excellent durability. Accordingly, silyl group-containing vinyl polymers have been widely used as paints, coating materials, adhesives, sealants and silane coupling agents. However, these polymers undergo hydrolysis of the terminal silyl group even in the absence of a catalyst, if moisture is present, and they gradually form siloxane linkages, thus eventually hardening. Therefore, they tend to gradually increase the viscosity during storage owing to reaction with water in the system. For such a reason, the silyl group-containing compounds are stored and used in the state that incorporation of water is prevented as much as possible. However, in case of repeatedly using the silyl group-containing compounds or in case of incorporating an additive such as a filler having a high water content into the silyl group-containing compounds, incorporation of water is unavoidable. Especially, when case that the content of the hydrolyzable silyl group is large, the storage stability becomes a problem.
The present inventors found that the silyl group-containing compounds can be formulated into a one component curing composition by adding a hydrolyzable ester compound as a stabilizer to a mixture of the silyl group-containing compound and a curing catalyst, and that a one component curing composition having an excellent storage stability can be obtained by using, from the viewpoint of dehydration, a reaction accelerator for accelerating the selective reaction between the hydrolyzable ester compound and water.
A primary object of the present invention is to provide a moisture curable composition having an improved storage stability.
A still further object of the invention is to provide a one component curing composition containing a silyl group-containing vinyl polymer and having an improved storage stability.
These and other objects of the present invention will become apparent from the description hereinafter.